Wireless Waffle - A whole spectrum of radio related rubbish
Ofcom proposes closure of stable doorsignal strength
Monday 19 January, 2015, 16:25 - Radio Randomness, Spectrum Management
Posted by Administrator
comtrend pltOn several past occasions, dating back to 2008, Wireless Waffle has reported on how several users of the short wave spectrum including radio amateurs, broadcasters, air traffic controllers and NATO, have raised concerns about interference caused by power-line telecommunications (PLT) devices (such as the Comtrend unit pictured on the right). PLT devices allow the use of home electrical wiring to carry computer data by injecting radio signals over the wires. As electrical wiring is designed to carry signals with a frequency of 50 Hz and not 5 MHz, the injected radio signals have a tendency to leak out everywhere and cause radio interference over a wide area.

Groups such as UKQRM and Ban PLT have long campaigned that PLT devices (also known as Power Line Adapters) should be taken off the market as they do not comply with the relevant emissions standards.

Over all of this period, the UK spectrum regulator Ofcom, has staunchly refused to accept that these devices contravene any regulations, though they have taken action in a number of cases where the interference they cause has exceeded even their expectations. Over the same timeframe, a number of other devices have also been found to cause high levels of radio interference, particularly cheap electrical devices, often imported on the grey market from China. These include things such as laptop power supplies, LED lighting and solar panel electrical controllers. Yet Ofcom continued to refuse to accept that anything needed doing.

It is therefore somewhat of a bolt from the blue that on January 15th, Ofcom released a consultation document, entitled 'Notice of proposals to make The Wireless Telegraphy (Control of Interference from Apparatus) Regulations 2015' in which it wishes to implement new controls over these devices by making it a criminal offence to operate them if they are causing interference to wireless telegraphy (e.g. radio services). Part of this seems to be driven by the fact that Ofcom were unable to deal with many interference complaints under existing regulations and that this could be regarded as a potential safety-of-life threat where the interference was caused to, for example, aeronautical services.

According to the consultation paper, there were 114 cases of interference reported in 2014, 'where undue interference was caused ... and capable of resolution'. Of those 114 cases, only 3 could be cured quickly using existing legislation and in the other cases it required voluntary action by the user of the equipment to bring about a solution. Under the proposed changes, all of these cases could be dealt with by law, meaning that instead of volunteering to fix the problem, users could be prosecuted if they didn't.

devil slop 2The big question has to be whether such a change would make any difference. Would those selling the devices stop doing so? Presumably not, as there is no law against selling them, just using them. Would they warn buyers of the new law? Not if it damaged sales. And what will happen if Ofcom threaten prosecution to someone who believes they have been using equipment quite legally, having purchased it legitimately, and having seen the various markings on the box that said it complied with the necessary standards? Will Ofcom then look silly for allowing such devices to have been sold in the first place? Sadly, the UK legislation on such things is still somewhat muddy. It is possible to sell, for example, FM transmitters, mobile signal boosters and even GPS jammers. It is just not legal to plug them in and use them.

ofcom horse boltingBan PLT are recommending that as many people as possible respond to the consultation, encouraging the changes to be implemented. No doubt organisations which manufacture or sell the devices will be arguing against the changes and so it is important that those who use the radio spectrum, especially the short wave spectrum, respond to show the strength of feeling.

There is an old saying in England, 'closing the barn door after the horse has bolted'. Effectively it means trying to solve a problem, after it has happened. The new powers proposed by Ofcom may have some effect in allowing Ofcom to convince users to turn off whichever device it is that is causing the problem, but it is by no means certain that the threat of 'turn it off or we will sue' is going to win anyone any friends, Ofcom, suppliers, BT and radio listeners alike.
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Hotel Wi-Fi in the spotlight againsignal strength
Wednesday 14 January, 2015, 12:52 - Spectrum Management
Posted by Administrator
Back in October of last year, Wireless Waffle reported that Marriott hotels had been fined by the FCC for deliberately interfereing with Wi-Fi networks in an attempt to try and force guests at their hotels to use the hotel's own extortionately priced WiFi service.

hotel girl laptopEarlier this month, the New York Times reported that several hotel chains have petitioned the FCC for permission to legally undertake such activities. The lengthy petition argues on several points that hotel operators (and other landlords) should be able to manage their networks to the extent that they can identify, and neutralise, anyone trying to offer WiFi services other than themselves, thereby maintaining a quality of service and level of security and safety for their users.

The main tenets of their argumentation seem to be:
  • That the type of sophisticated monitoring and enforcement activities they are proposing do not constitute harmful interference but are good network management practices;
  • That their networks are established using best industry practices to maximuse performance and that non-approved WiFi hotspots mess about with this and degrade their service;
  • That the Part 15 rules that allow users to establish WiFi hotspots require those users to be located on a property where the user has "direct or indirect ownership or leasehold" and that this does not apply to hotel guests.

It then goes on to liken a university applying bandwidth caps to student usage as being a similar network management practice, but one that no-one would argue with and therefore, by implication, the practice of neutralising the threat of miscreant networks should also just be considered best practice.

hotel wifi logoNotwithstanding any of the above, WiFi networks, whether operating under the Part 15 rules in the USA, or in most other countries are permitted access to the radio spectrum on a 'non interference' basis. This means that they are not permitted to interfere with any other users, and that they must accept any interference caused by any other users. In effect, they have no protection from interference at all. What the hotels are trying to do is run a commercial grade wireless internet service in this spectrum. If this were possible, and it were possible to provide the quality of service that users would seek, would it not follow that the big commercial operators would want to do the same thing too. Free WiFi hotspots in a coffee shop is one thing, but trying to provide a guaranteed service is another.

tp link wr702nThe hotel chains argue that when they enter into an agreement to provide services for, for example, a conference, they agree to some quality of service parameters for their WiFi service. This is their own silly fault! It's like guaranteeing your guests that it won't rain this week. It's not something that the hotel has control over. Not least, the WiFi bands are used by a myriad of other, non-WiFi devices, that could equally upset the performance of the hotel's WiFi networks including their very own microwave ovens!

One has to question whether these hotels would be so keen to conduct such complex network management if they offered their WiFi service for free. Hotel visitors should vote with their feet and choose hotels that do offer Free WiFi. Marriott and its friends would soon change their tune, not least as it appears that cheaper hotels have the best WiFi! Oh, and don't forget to take your Wireless Nano Router to set up your own network nice and easily too!

Post Script: It seems that just a day after writing this, the BBC report that Marriott has backed down. Was it something we said...?
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Why-Fi No-Fly Zonesignal strength
Friday 7 November, 2014, 17:20 - Spectrum Management, Much Ado About Nothing
Posted by Administrator
Various news web-site including CNN and the BBC report that American Airlines flight 136 due to fly from Los Angeles to London on October 26 was delayed by almost a day when a passenger sitting on the aircraft noticed a WiFi network named 'Al-Quida Free Terror Nettwork'. As a result, the aircraft was emptied and a search conducted by US Customs and Border protection officials but the source of the offending WiFi signal was never found. No doubt the misspelling of 'Al Qaeda' and 'Network' enhanced the level of terror indicating, as it does, that the person who set up the network was potentially:
  • someone for whom English was not their first language;
  • a dimwit whose IQ was far below average;
  • someone with scant regard for spelling in an infidel's tongue; or
  • a person deliberately trying to mask their true intentions by appearing as one of the above.
Any of the cases above would no doubt strengthen a belief that the network was established by a terrorist group to whom any and all of those characteristics could apply.

As the BBC notes:
Many broadband subscribers re-name their home wi-fi network to personalise it.

ideal cleaning wirelessBack in 2007, Wireless Waffle undertook a survey of WiFi channel usage which found networks with such kooky names as 'Gary Barlow', 'Slapheads Network', 'Toast' and 'Fraudulent'. The practice of personalising WiFi network names (or SSIDs as they're technically known) is not a new one and whilst naming a network after a terrorist organisation is clearly a very bad idea (especially whilst at an airport) there's no law against it. If just setting an SSID to such a name can disrupt flights at a busy airport, then it opens the door to widespread misuse of, for example, the WiFi tethering options on mobile phones, to conduct all kind of Rabelaisian ruses.

Many airports and other major venues and events (such as at the London Olympic Games) use radio spectrum monitoring equipment to check for people using unlicensed frequencies as the wireless landscape in such places is very complex with many networks sharing neighbouring frequencies. Careful planning is essential to ensure that the myriad of users do not interfere with each other (especially to the safety critical air-ground systems for example) and monitoring is vital in keeping the airwaves free of signals that could cause problems.

Maybe airports and other establishments that might be the target of people intent on causing havoc with their naughtily named WiFi SSIDs could take a leaf out of the book of Marriott and also install WiFi monitoring systems that would allow naughty network names to be traced and closed down before they caused multifarious mayhem.
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UK Hams Get New 'Moonlight' Channelssignal strength
Friday 31 October, 2014, 08:00 - Amateur Radio, Spectrum Management
Posted by Administrator
Back in the early days of citizens band (CB) radio in the UK, when the 40 available channels were busy and bustling, some enterprising operators found that by changing the voltages on the pins of some of the integrated circuits inside their CB radios (the PLL), it was possible to make them operate on channels immediately below the normal 40. These channels were only used by those 'in the know' and were illegal to use (then again when did legality ever bother CB operators?) They became known as the 'moonlight' channels referring no-doubt to their somewhat illicit status and the fact that they tended to be busiest late at night.

moonlight channelsMove forward over 30 years and as of today (31 October 2014), radio amateurs in the UK have access to an additional piece of VHF spectrum from 146 to 147 MHz. Access to this extension to the 2 metre band is only through a notice of variation (NoV) which can be applied for by any full licensee on the RSGB web-site. The new spectrum will initially be available for just 12 months though Ofcom may automatically extend this if they see fit and is on a non-interference basis meaning that radio hams must not cause interference to any legitimate users (e.g. in neighbouring countries) and must accept any interference that those users cause.

There are other limitations notably that the maximum transmitter power is 25 Watts, antenna height must not exceed 20 metres and in Scotland (and within 40 km of Scotland) the upper band edge is 146.9375 MHz.

Given the date of the release of this new piece spectrum to radio hams and its uncanny similarity to the original CB band extension (being immediately adjacent to the normal allocation) Wireless Waffle suggests that these new channels be also named the moonlight channels. To celebrate the release of the new VHF moonlight channels, we have compiled a list of one hundred horrible Halloween hits to dampen the spirits at any party.

Anyone for a natter on the newly designated moonlight calling channel of 146.666 MHz tonight?
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